I have this terrible feeling that the game story moves on whether I do or not...

I was happily finishing up my second story addition to Red Rocket, when got the message "Clearing the way for Sanctuary Hills failed".

I may postpone missions - but I don't fail them.

I rolled back a couple of hours and headed out to see what was wrong.

I entered the Quest target (no spoilers) - and the mission failed again. Sky full of BoS actively engaging - something.

Rolled back further, losing a ton of settlement improvements and tried again.

This time, no BoS in the skies and mission completed successfully. And at least settlement improvements are easier when you have done it once.

Would love to know what else the game is doing well I am busy building...

So warning - ignore the main story at your own risk. Main factions seem to be doing their own thing.

Just done that mission. It's not actually a main story mission but there are other missions too that are time sensitive like the defend a certain settlement missions

I was specifically worried about this mission because a successful completion launches the next one - Clearing the way for Red Rocket. Not a chain I want to break.

The Defend missions just cost you some resources if you fail - so I don't worry if I fail one of those.